It's that time of the campaign when the Oregon legislative candidates are throwing everything they can at each other. If I tried to follow it all, I'd never get to anything else.

But a dust-up in the heated Washington County race between Sen. Bruce Starr, R-Hillsboro and his Democratic challenger, Rep. Chuck Riley of Hillsboro, caught my attention because it says something about the life of legislators.

Riley on Monday filed an election complaint - which sometimes can be a serious thing but is sometimes just a cheap campaign tactic - questioning whether Starr was siphoning money out of his campaign fund by pocketing excessive amounts for mileage.

Since the start of 2009, Starr has claimed expense reimbursements of nearly $12,400 - which at 50 cents a mile, the IRS rate he claimed - would add up to nearly 25,000 miles.

Oddly enough, most of that mileage - at least 16,000 - appeared to come after the Legislature had ended and he didn't have to make the daily trek to Salem. And on seven occasions, it was a nice round number, like $500, which struck Riley as suspicious.

"Oh, absolutely, I'm skeptical," said Riley. "This mileage is (equivalent to going) around the world and a couple thousand miles in just 20 months."

Starr insisted it's a non-story, a "desperate attack by a desperate politician without a record to run on."

Starr said that as one of the state Legislature's top transportation experts, he frequently travels around the state. More recently, he described a dizzying array of campaign travel, often to pick up donations. In recent days, he said, he's met with lobbyists (and their checkbooks) in Salem, Wilsonville, Bridgeport Village and Portland.

Starr allowed that the even reimbursement amounts look funny. He said he took lesser amounts out of his campaign fund when it was running low, but he said he's caught up now. (Riley questions that, saying Starr has appeared to have a pretty decent balance in his campaign fund since the end of the 2009 session).

I did a spot check of legislators in the Portland area and didn't find anyone who had collected as much mileage as Starr from his campaign fund. Some, such as Riley, a retired IT consultant, said he doesn't charge his campaign fund for mileage at all.

Under state law, legislators are allowed to use campaign money for expenses related to their legislative duties, but they can't convert it to personal use.

Riley says the expenses of going back and forth to a session ought to be covered by the $116 per diem that lawmakers get while they are in session. It's tax-free for legislators who don't live near the Capitol.

But Starr, who works as a public affairs consultant, says the per diem "replaces my income when I'm full-time in the Legislature." So he pays his mileage expenses with his campaign fund.

Barry Pack, the deputy secretary of state, said Elections Divisison officials will review the complaint to see if there is any merit to it. Starr says he has the mileage records to show nothing is amiss.

In the end, I'm reminded how relatively small amounts of money can loom large to legislators who don't get paid a lot. And how campaigns can sometimes revolve around things that seem small in comparison to a state budget that runs into the billions of dollars.